Integration schemes and enabling technologies for three-dimensional integrated circuits

Various integration schemes and key enabling technologies for wafer-level three-dimensional integrated circuits (3D IC) are reviewed and discussed. Stacking orientations (face up or face down), methods of wafer bonding (metallic, dielectric or hybrid), formation of through-silicon via (TSV) (via first, via middle or via last) and singulation level (wafer-to-wafer or chip-to-wafer) are options for 3D IC integration schemes. Key enabling technologies, such as alignment, Cu-Cu bonding and TSV fabrication, are described as well. Improved performance, such as lower latency and higher bandwidth, lower power consumption, smaller form factor, lower cost and heterogeneous integration of disparate functionalities, are made possible in the next generation of electronics products with the realisation of 3D IC.